Now, there are so many versions of internet browsers that it tends to be a bit messy. This is especially true for Firefox.

Different release life cycles

Here’s a brief history of the three main browsers. Sorry Opera and Safari fans…

Up to version 3, Mozilla team used to release a major version of Firefox once a year or every two years :

Version 1 in 2004

Version 1.5 in 2005

Version 2 in 2006

Version 3 in 2008

Version 3.5 in 2009

Version 3.6 in 2010

The differences between each version are significant as on functionality and the look & feel as on the layout and javascript engine.

Internet Explorer, a web dinosaur, follows a similar life cycle. There is a correlation between Windows releases and IE version increment.

Version 1 mid-1995 (Windows 95)

Version 2 end 1995

Version 3 in 1996

Version 4 in 1998 (Windows 98)

Version 5 in 1999

Version 6 in 2001 (Windows XP)

Version 7 in 2006

Version 8 in 2009 (Windows Vista)

Version 9 in 2011 (Windows 7)

Version 10 coming in 2012 (Windows 8)

I don’t forget the youngest browser on the market : Chrome. In only two years of existence, Chrome has become one the most popular browser and has overtaken Firefox. Version increment is faster with several releases a year (or even two releases a month). Updates have become so routine that Google barely even mentions them anymore…

Version 1 end 2008

Version 2 mid-2009

Version 3 end 2009

…

Version 8 end 2010

…

Version 16 end 2011

Version 17 coming early 2012

Firefox in trouble

The conclusion is obvious. Chrome, which has been released 4 years after Firefox, is displaying a version number much more higher : Firefox 3.6.13 and Chrome 8 in early 2011. The longevity of IE is such that Microsoft does not need to speed up its release cycle (IE 9 in 2011).

Let’s take a user who has the choice between an application X in version 2 and an application Y in version 12 and knowing that both applications have similar features. Unless strong constraints, it is likely that he will use the application Y. A higher number version means a better, up-to-date, stable and reliable application with the latest features. Of course, this is not necessarily true, but it’s a perfectly legitimate and natural choice.

Mozilla reactions

To prevent losing market share and to keep up with its competitors, Mozilla introduced a fast release schedule after Firefox 3.6 (every six weeks) :

Version 4 in March 2011

Version 5 in June 2011

Version 6 in August 2011

Version 7 in September 2011

Version 8 in November 2011

Version 9 in December 2011

Version 10 coming end January 2012

Firefox and IE are in the running for 2012 with a version number in double-digit. At this rate, Chrome would reach version 30 (!!) by the end of the year.

Firefox, available in several “flavors”

At the same time, Mozilla has introduced new distribution channels. We used to have a Beta and Stable channel. Now, the existing “Nightly” channel has been highlighted in the process and we also have an “Alpha” channel, which sits between Nightly and Beta (a kind of pre-beta).

This is the agile concept of continuous integration, with the building of the latest software version every day (nightly build) and the possibility to release a new version more often. User has access to the latest features, but it means there will be bugs and issues. Indeed, goal is to provide some feedback for the development team, as soon as possible, in order to include correction and enhancement in beta and stable revisions. In the same time, Mozilla has found a more recognizable name to its alpha channel : “Aurora”. The community has also designed new logos and a dedicated web page.

The different Firefox logos

Since version 4.0, Firefox is now available for mobile devices, with stable, Beta and Aurora channels like the Desktop version. Mobile and Desktop versions share the same version increment.

ESR, the new Firefox flavor in 2012

In early 2012, Mozilla announces a new version of Firefox (again !) with an extended support, Firefox ESR (Extended Support Release).

Firefox ESR is a variation of the Desktop version designed for enterprises with a slower release cycle that allows organizations more time to certify and test new releases of the browser.

Firefox release plan

Firefox 10 will be the first Extended Support Release and will incorporate security updates. The ESR release cycle will be slower and similar to the old one (before version 4) with a major release every year. For example, a company will have to update from Firefox ESR 10.x to ESR 17.0 (17 is not arbitrary, an ESR version will be supported for one year with security updates).

Note :

Because Firefox 3.6 is still receiving security updates (it will until April 24th, 2012), it can be seen as an unofficial ESR version. Companies would be well advised to update to Firefox 10.0 ESR (planned for the 31st of January 2012) when Firefox 3.6 will not be supported anymore.

Diagram and key dates above are provided for information only, this is a draft plan and there will probably be some changes.

What’s next ?

Is this multiplicity of versions will make Firefox losing users ? Is it meaningful to keep high version numbers ? Will Microsoft have to adopt a rapid release development cycle ? Late 2013, will Chrome be in version 50 ?

So many questions unanswered, but I hope this article has helped you to find your way in all these versions…

Chrome / Chromium browser has the annoying habit of keeping all of its older versions on the system. Useful to return to the previous version if it fails to install the new one, this history tends to reduce your disk space. When you know that a version is about 80 Mb, it’s a no brainer !

As far as I know, the browser does not backup versions. It completely uninstalls the old and installs the new one (unlike Windows, update in not possible from the browser).

Then, delete all folders matching old versions (except the latest !). For example, the folder “12.0.742.91” can be removed if the folder “12.0.742.100” exists and corresponds to my current version of Chrome / Chromium.